The present invention relates generally to surgical instruments and more specifically to surgical clip appliers used for applying ligating clips to blood vessels and other tubular ducts or tissue.
In surgical procedures, it is frequently necessary to ligate ducts, such as blood vessels, or other severed tissue. For this purpose, it is well-known to use surgical clip appliers, such as that described in U.S. Pat. No. 3,439,522, to apply surgical clips to a duct or tissue to be ligated. Such clip appliers typically have a scissor-like construction, with a pair of movable handles which are grasped by the surgeon, and a pair of movable jaws opposite the handles into which a surgical clip is placed. Such clips usually have a pair of connected legs to form a U or V shape. When the handles are closed, the jaws close the legs of the clip together on the vessel or other tissue to be ligated.
In some surgical procedures, it is desirable to use a clip applier which is configured to allow tissue ligation in inaccessible areas of the surgical site. To address this need, a number of surgical clip appliers have been developed with the jaws extended from the handles at a distance, or with the jaws oriented at various angles. Examples are described in U.S. Pat. Nos. 3,777,538, and 4,440,170.
Other known clip appliers, such as that described in U.S. Pat. No. 4,616,650, provide for retaining multiple clips in the applier and feeding the clips toward the distal end of the applier, thereby permitting the surgeon to apply multiple clips at various places in the surgical site without removing the clip applier from the site to place another clip in the jaws. In some of these known devices, the clip applier is designed to accommodate an interchangeable cartridge containing multiple clips. An example is seen in U.S. Pat. No. 3,675,688.
In some surgical procedures, however, known clip appliers suffer certain drawbacks. In particular, known clip appliers have significant limitations when used in laparoscopic surgical procedures. Such procedures usually involve distending the abdominal cavity away from the underlying organs to improve access and visibility, using gas insufflation or a mechanical distension technique. Several small incisions are made in the abdomen through which are inserted trocar sleeves--plastic tubes designed to provide a sealed entryway into the abdominal cavity. Surgery is performed using long-handled instruments inserted through the trocar sleeves, with a lens connected to a video monitor providing visibility of the abdominal cavity.
Clip appliers used in laparoscopic surgery must be elongated so as to reach through the abdominal wall to the appropriate site, and preferably should not require removal from the abdominal cavity to reload clips after each clip is applied. The distal portion of such clip appliers must be of such dimension so as to pass through a trocar sleeve. Of particular importance is the orientation of the jaws at the distal end of the clip applier. During the course of surgery, ducts or tissue to be ligated will be oriented at various angles relative to the abdominal wall. Because of the limited range of motion afforded by the trocar sleeve, the surgeon depends on the orientation of the jaws to properly correspond with the angle of the duct or tissue to be ligated. In some cases, a surgeon may need to ligate a vessel or other tissue at an angle of up to 90.degree. or more relative to the distal end of the clip applier. Further, because of the limited visibility of the surgical site and the limited maneuverability of instruments through the trocar sleeve, once a surgeon has positioned a clip applier at a desired site, s/he may want to apply two or more clips along a portion of duct or tissue without pulling the clip applier away from the site to position additional clips in the jaws.
In addition, the distally-oriented jaws of known clip appliers suffer from the inability to exert tension upon a duct or portion of tissue to which a clip is to be applied. Any repositioning of tissue must be achieved by pushing on the clip applier, exerting a compressive force on the tissue. This tends to push the tissue against underlying tissue, which may obstruct visibility, and can interfere with the application of the clip. Moreover, the unintentional application of a clip to underlying tissue, e.g. an organ or blood vessel, can pose a serious risk to the patient.
For these reasons, it would be desirable to provide improved methods and apparatus for applying surgical clips which permit application of multiple clips without removing the apparatus from the surgical site, and at the same time orient the clips at various angles relative to the distal end of the clip applier, including perpendicular thereto. The methods and apparatus should be usable in laparoscopic surgery and other such procedures wherein a very small incision is made. In particular, the apparatus should be capable of passing through a trocar sleeve having a diameter of 10 mm. It would be particularly desirable if the clip applier jaws could be rotated about 360.degree. from a point outside of the surgical area and proximate to the point where the clip applier is held by the user. The apparatus and method should further allow the surgeon to apply clips in a controllable manner, permitting the clip to be closed as slowly or quickly as the surgeon desires. In addition, the apparatus and method should allow the user to exert tension on a portion of tissue for more effective positioning, so as to improve visibility of the tissue to be ligated, as well as to avoid interference with nearby tissue.